She joins a growing roster of stars coming aboard the untitled project, which is from Arrow creators Greg Berlanti, Andrew Kreisberg and Marc Guggenheim. Other actors in the mix include The Flash's Wentworth Miller (Leonard Snart/Captain Cold), Dominic Purcell (Mick Rory/Heatwave) and Victor Garber (Dr. Martin Stein/one half of Firestorm). Also signed on are Arrow's Brandon Routh as Ray Palmer/the Atom and Caity Lotz, whose Arrow character Sara Lance/Canary died earlier this season.

Renee is best known for her work on stage, where she made her Broadway debut in the new adaptation of Big Fish in 2013. Last year she replaced Patina Miller as The Leading Player in the Broadway revival of Pippin.

Arrow and The Flash have already found success with a series of crossover episodes, and it is possible more characters from those shows could appear in the spinoff, which is described as a supehero team-up series. Both shows have already experimented with teaming up villains as well.

The potential Arrow/Flash team-up comes as Berlanti and Kreisberg are prepping CBS' DC Comics take on Supergirl, which has a series commitment at the network. The potential spinoff also hails from Warner Bros. Television and Greg Berlanti Productions' topper Sarah Schechter.